Video pneumatic otoscopy for the diagnosis of conductive hearing loss with normal tympanic membranes.

OBJECTIVE

To evaluate the usefulness of video pneumatic otoscopy (VPO) for the diagnosis of conductive hearing loss (CHL) with normal tympanic membranes (TM).

STUDY DESIGN

Prospective study.

SETTING

Tertiary care hospital.

SUBJECTS AND METHODS

Thirty-seven ears with CHL and 9 control ears with normal TMs were included. The VPO was performed preoperatively in all patients. The authors captured TM images in 3 stages of the VPO (static, positive, and negative pressure stage) in all subjects and measured the amount of relative position differences of the umbo. Pure-tone audiometry and temporal bone computed tomography (TBCT) were performed preoperatively. The possible causes of hearing loss were evaluated during exploratory tympanotomy in the patients with CHL.

RESULTS

Fifteen patients had stapedial fixation, 10 had fixation of the malleus or incus (MIF), and 12 had ossicular discontinuity. The positional differences between the negative and positive pressure stage of the MIF group were significantly smaller between the CHL and control groups (P = .001). The air-bone gap showed no significant difference among the CHL groups. The sensitivity, specificity, and diagnostic accuracy of the VPO for the diagnosis of MIF, with a cutoff value of 1.5% or less in terms of the movement of umbo, were 80.0%, 92.6%, and 89.2%, respectively. These findings were comparable to those of the TBCT, which were 90.0%, 85.2%, and 86.5%, respectively.

CONCLUSION

The VPO is a simple, noninvasive, and accurate tool for the differential diagnosis of CHL with a normal TM.